From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2343C10F00 for ; Mon, 18 Mar 2019 17:19:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74C3820863 for ; Mon, 18 Mar 2019 17:19:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="YkzThGw7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727883AbfCRRSG (ORCPT ); Mon, 18 Mar 2019 13:18:06 -0400 Received: from mail-qk1-f202.google.com ([209.85.222.202]:34873 "EHLO mail-qk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727868AbfCRRSF (ORCPT ); Mon, 18 Mar 2019 13:18:05 -0400 Received: by mail-qk1-f202.google.com with SMTP id t13so15350988qkm.2 for ; Mon, 18 Mar 2019 10:18:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=LfpjTjIWpAUqgBuBr+ROlRDq3TWjVWHbA3wqyLv7Gqg=; b=YkzThGw7U5bxwuGivZfG7gXjy3sbFeGI9LQQNwpjKesMWYXA6dWvmlyTVIDVds3jdT 99Hv46CfyNGepDjQmBrGdjnE8DmIFRJxBJqNXjHLIWC7+99xjXgyacIB4V4zSxrfGRS1 gCdVGS/MQBILBUagjA0XfHFo8FDflJm4SJEr94PsmlNdR79rNuZTcqAgPDOmgM2h8uU1 X27jM72pTPp4w4jfVrzQIbmq9wd3O59csXywpy8yafGddFfq57LOwhbAfJSUMg2BvGCJ ay4PGD3jH0Ph4L+WAj6gW2ezv9U1Ktw+Hx+TJhzvpdvgFTaZaxSZHrZdwWAc4E0uG5zJ mTGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=LfpjTjIWpAUqgBuBr+ROlRDq3TWjVWHbA3wqyLv7Gqg=; b=B0FXXJOs7jRzxgKrmhSjSnLDqgbHcdthSMT4xrm6An0tIHRe405K/p71N0MMP0qhrJ yJI7Lao7cCEa+ulN6qbykWOepZRmKlUmGlzL1ykplwY5tI6UeTbhL431LrFN/tKSmCux MGW3s7m3WDoK4s390szdk9RBkEv3zljpGm/382sbY9O34FHdvhwFGiPISInxTk+ZU5EO LvE9bYjPtW7gqSrJdIjD+0upuPQaB20lRUD8299QWewZ/96tlPGtICdgSrk0Dr58kDfU Sg1+O2h4GUd2xVtyMtV01Q2k5CyqjCIbCdgExeqruaGR1F5tMNEsY/Ycogg/pQ8C6trR KoAg== X-Gm-Message-State: APjAAAX54licYiC8cvg0NT6l7ixmb9jzdrOVClTM503JZZZhj29NqAOP 7queruqHrDS5qEDw5gb+vFr05du3y7IF5oKv X-Google-Smtp-Source: APXvYqwvaFpE6Rrk389WuFNgjhFYIoDJPXDJycXik4soUJpzaOpECOFFeWGr/7DmdYgwI9v4deSBDrsPhVpuummk X-Received: by 2002:aed:3a42:: with SMTP id n60mr10517091qte.62.1552929484433; Mon, 18 Mar 2019 10:18:04 -0700 (PDT) Date: Mon, 18 Mar 2019 18:17:37 +0100 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.225.g810b269d1ac-goog Subject: [PATCH v12 05/13] mm, arm64: untag user pointers in mm/gup.c From: Andrey Konovalov To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Shuah Khan , Vincenzo Frascino , Eric Dumazet , "David S. Miller" , Alexei Starovoitov , Daniel Borkmann , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This patch is a part of a series that extends arm64 kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. mm/gup.c provides a kernel interface that accepts user addresses and manipulates user pages directly (for example get_user_pages, that is used by the futex syscall). Since a user can provided tagged addresses, we need to handle this case. Add untagging to gup.c functions that use user addresses for vma lookups. Signed-off-by: Andrey Konovalov --- mm/gup.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index f84e22685aaa..3192741e0b3a 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -686,6 +686,8 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, if (!nr_pages) return 0; + start = untagged_addr(start); + VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); /* @@ -848,6 +850,8 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm, struct vm_area_struct *vma; vm_fault_t ret, major = 0; + address = untagged_addr(address); + if (unlocked) fault_flags |= FAULT_FLAG_ALLOW_RETRY; -- 2.21.0.225.g810b269d1ac-goog